Geometry Nodes: Rotate positions about a point?
Interesting question!


The blend file above contains a moving weight modifier and two rotating pivot points. The mesh is rotated around the pivot points influenced by the weight value by geometry nodes.


Add the weighted_rotation node network to your target, provide it a object as pivot point and you're done. The weight group is optional; if it's not available the modifier just rotates around the pivot point.
Enjoy!